When I showed this manuscript to my friend, Chief Detective-Inspector Alleyn, of the Criminal Investigation Department, he said:

“It’s a perfectly good account of the Unicorn case, but isn’t it usual in detective stories to conceal the identity of the criminal?”

I looked at him coldly.

“Hopelessly vieux jeu, my dear Alleyn. Nowadays the identity of the criminal is always revealed in the early chapters. ”

“In that case,” he said, “I congratulate you.”

I was not altogether delighted.

On May 25th Arthur Surbonadier, whose real name was Arthur Simes, went to visit his uncle, Jacob Saint, whose real name was Jacob Simes. Jacob was an actor before he went into management and had chosen Saint as his stage name, and stuck to it for the rest of his life. He made bad jokes about it—“I’m no Saint”—and wouldn’t allow his nephew to adopt it when he in turn took to the boards. “Only one Saint in the profession,” he roared out. “Call yourself what you like, Arthur, but keep off my grass. I’ll start you off at the Unicorn and I’ll leave you the cash — or most of it. If you’re a bad actor you won’t get the parts — that’s business.”

As Arthur Surbonadier (“Surbonadier” had been suggested by Stephanie Vaughan) walked after the footman towards his uncle’s library, he remembered this conversation. He was not a bad actor. He was an adequate actor. He was, he told himself, a damn' good actor. He tried to stiffen himself for the encounter. A damn' good actor with personality. He would dominate Jacob Saint. He would, if necessary, use that final weapon — the weapon that Saint knew nothing about. The footman opened the library door.